Contact your Medicare Part D or Medicare Advantage plan's Member Services department to verify your method of payment. (The toll-free number for Member Services is on your Member ID card and most of your plan's printed plan information.)
If your Social Security premium withholding has not been set up already, and you still want Social Security to withhold premiums, you may need to pay the first few months of your premium directly to your plan.
Your plan also can help you start to withhold premiums for the future.
If there is any question about whether your premium is being withheld, your plan can check this with Medicare.
You can also contact Medicare directly at 1-800-MEDICARE (1-800-633-4227) and ask them to check if your premium withhold is taking place.
Important Point: Remember, it generally takes two months after you enroll and choose this payment option for the premium withhold to take effect.
(Source: U.S. Department of Health & Human Services)